1. Field of The Invention
The invention relates to aromatic carbonate and polyarylate polymers of controlled molecular weight and more particularly relates to such polymers end-capped with a hydroxyaryloxazoline.
2. Brief Description of the Prior Art
It is known that in certain procedures of producing aromatic carbonate, ester-carbonate and polyarylate polymers from dihydric phenols, a carbonate precursor such as phosgene, and/or an aromatic diacid such as isophthalic or terephthalic acid, small amounts of weight regulators (chain terminators) can be used to provide end or terminal groups on the polymer and thereby control the molecular weight. Such materials include monofunctional phenols such as phenol and p-tertiary-butylphenol. The purpose of using a chain terminator has been to affect physical properties of the polymer, such as melt flow characteristics and thermal stability.
The prior art also disclosed several other types of compounds that act as chain terminators for the carbonate, ester carbonate or polyarylate polymers. Thus, U.S. Pat. No. 3,085,992 discloses alkanolamines as chain terminators; U.S. Pat. No. 3,399,172 teaches imides as chain terminators; U.S. Pat. No. 3,275,601 discloses that aniline and methylaniline function as chain terminators in the interfacial polymerization process for producing polycarbonates; and U.S. Pat. No. 4,001,184 discloses primary and secondary amines as molecular weight regulators for polycarbonate. Furthermore, U.S. Pat. No. 3,028,365 discloses that aromatic amines and other monofunctional amine compounds can be used to control or regulate the molecular weight of polycarbonates, thereby forming aryl urethane terminal groups. Aromatic polycarbonates having urethane end groups are disclosed in U.S. Pat. No. 4,111,910. These polycarbonates are prepared using a terminating amount of ammonia, ammonium compounds, primary cycloalkyl or aralkyl amines and secondary cycloalkyl, alkyl or aralkylamines.
I have found that polycarbonate and polyarylate resins prepared by the known interfacial polymerization method may be end-capped with hydroxyaryloxazolines to control molecular weight. In addition to affecting desirable physical properties, advantageously, the end-capped polymer chains are reactive and can subsequently react with a wide variety of other polymers bearing functional groups such as carboxylic acids, anhydrides, phenolic hydroxyls, amines, mercaptans, epoxides and like groups. It is our belief that no one has disclosed the use of a terminator which can subsequently react with other polymers. The reactive polycarbonate resins of the invention are uniquely reactive with a wide variety of polymers and may be used to form block and graft copolymers with appropriate functionalized polymers. The block and graft copolymers so prepared have excellent property profiles and are useful as injection molding and extrusion resins or as compatibilizers for polycarbonate or polyarylate resin blends.